HttpUrlConnection: how to get the XML response into a String?

Question

I am using HttpURLConnection to post to a REST API. I still have not successfully posted anything, so I'm trying to get back the XML response that should be coming from the API.

Here is the segment of the code that I've put together that is giving me the issues:

// Process response - need to get XML response back.
InputStream stream = connection.getInputStream();
connection.disconnect();

BufferedReader br = new BufferedReader(stream);
String result;
String line;
while ((line = br.readLine()) != null) {
    System.out.println(line);
    result += line;
}
br.close();

The compiler is not happy with this line (the suggested fix is "Change type of stream to reader"):

BufferedReader br = new BufferedReader(stream);

Does anyone have any suggestions as to how I might do this properly? Any help appreciated.

Complete code here:

package com.gwt.HelpDeskTest.server;

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;

import com.google.gwt.user.server.rpc.RemoteServiceServlet;
import com.gwt.HelpDeskTest.client.HelpDeskTestService;
import com.gwt.HelpDeskTest.shared.HelpDeskTestException;

@SuppressWarnings("serial")
public class HelpDeskTestImpl extends RemoteServiceServlet implements HelpDeskTestService {

    @Override
    public String postToRemoteServer(String serviceUrl) throws HelpDeskTestException {
        try {
            final String serverPath= "http://helpdesk.rmi.org/sdpapi/request/";     
            final String serverParameters = "OPERATION_NAME=ADD_REQUEST&TECHNICIAN_KEY=D4ADD3A3-9CD4-4307-932B-29E96BCFA5B6&INPUT_DATA=%3C?xml%20version=%25221.0%2522%20encoding=%2522utf-8%2522?%3E%3COperation%3E%3CDetails%3E%3Crequester%3EBetsy%20Leach%3C/requester%3E%3Csubject%3ETest%3C/subject%3E%3Cdescription%3ETesting%20curl%20input%20again%3C/description%3E%3C/Details%3E%3C/Operation%3E"; // Put parameters here for testing.

            // trying HttpURLConnection instead of a plain URLConnection

            URL url = new URL(serverPath); 
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();           
            connection.setDoOutput(true);
            connection.setDoInput(true);
            connection.setInstanceFollowRedirects(false); 
            connection.setRequestMethod("POST"); 
            connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded"); 
            connection.setRequestProperty("charset", "utf-8");
            connection.setRequestProperty("Content-Length", "" + Integer.toString(serverParameters.getBytes().length));
            connection.setUseCaches (false);

            DataOutputStream wr = new DataOutputStream(connection.getOutputStream());
            wr.writeBytes(serverParameters);
            wr.flush();
            wr.close();

            // Process response - need to get XML response back.
            InputStream stream = connection.getInputStream();
            connection.disconnect();

            // Put output stream into a String
            BufferedReader br = new BufferedReader(stream);
            String result;
            String line;
            while ((line = br.readLine()) != null) {
                System.out.println(line);
                result += line;
            }
            br.close();

            System.out.println(result);
            return result;
        } 
        catch (final Exception e) {
            System.out.println(e.getMessage());
            throw new HelpDeskTestException();
        }
    }
}

Answer 1

I have two observations.

1. Move connection.disconnect(); towards the end, where you are done with reading i.e. after the br.close(); line.

2. Follow Below sequence:

   InputStream stream = connection.getInputStream();
   InputStreamReader isReader = new InputStreamReader(stream ); 
   
   //put output stream into a string
   BufferedReader br = new BufferedReader(isReader );
   

Hope that works!

Answer 2

Buffered reader does not accept input stream directly, it accepts only reader objects. Wrap the input stream in input stream reader and pass it to buffered reader.

BufferedReader br = new BufferedReader(new InputStreamReader(stream));